JP6364381B2 - Throttle device and refrigeration cycle system including the same - Google Patents

Description

  The present invention relates to a throttling device and a refrigeration cycle system including the same.

  As a refrigeration cycle system in an air conditioner, a system having a differential pressure type throttle device instead of a capillary tube as a throttle device has been proposed. The differential pressure type throttling device can optimally control the refrigerant pressure between the condenser outlet and the evaporator inlet in order to efficiently operate the compressor according to the outside air temperature, and can change the rotation speed of the compressor. Also in the refrigeration cycle system, the refrigerant pressure is optimally controlled in accordance with the rotational speed of the compressor from the viewpoint of labor saving. For example, the expansion device is joined to a primary side pipe connected to the condenser at one end where the refrigerant is introduced, and joined to a secondary side pipe connected to the evaporator at the other end where the refrigerant is discharged. ing.

  For example, as disclosed in Patent Document 1, a differential pressure type throttle device includes a valve body that adjusts the opening of a valve opening of a housing, a guide skirt that has a plurality of holes and guides the movement of the valve body. And a coil spring that biases the valve body toward the space of the inflow port of the housing. The valve opening of the housing described above is connected to a condenser (heat radiator), and the outlet of the housing is connected to an evaporator.

  In the vicinity of the valve body in the above-described guide skirt, a plurality of holes forming a refrigerant flow path are formed. The cylindrical outer surface of the guide skirt extending toward the outlet of the housing contacts the inner wall of the housing, so that the movement of the valve element is guided against the biasing force of the coil spring. As a result, the valve body stops at a position where the forces applied through the valve opening of the housing and the outlet of the housing are balanced, so that the opening degree of the valve opening is determined by the elastic force exerted by the coil spring on the valve body. The Rukoto.

Japanese Patent No. 3528433

  In the differential pressure type throttle device as described above, the refrigerant is in a relatively unstable liquid-gas state downstream of the valve port of the housing. The components contained in the refrigerant and refrigerating machine oil are eluted and formed in the sliding part where parts such as the part where the cylindrical outer surface of the guide skirt, which is the downstream part of the valve port, contacts the inner wall of the housing slides. In some cases, the eluate or wear powder, or a compound of the eluate and wear powder adheres and accumulates. Such eluent and wear powder that causes sliding resistance in the guide skirt adversely affects the flow rate characteristics of the throttling device.

  In view of the above problems, the present invention is a squeezing device and a refrigeration cycle system including the squeezing device, and the eluate or wear powder of components contained in the refrigerant and the refrigerating machine oil, An object of the present invention is to provide a throttling device capable of suppressing foreign matters such as compounds from adhering to a sliding portion in a throttling device disposed downstream of a valve port, and a refrigeration cycle system including the throttling device.

In order to achieve the above object, a throttling device according to the present invention is arranged in a pipe for supplying a refrigerant and has a tube main body having both ends of open ends communicating with the pipe, and at least one communicating with the tube main body. A valve seat having a valve port formed in a guide tube having two open ends, and at least one communication hole formed adjacent to the valve seat in the guide tube and communicating with the inner peripheral portion and the outer peripheral portion of the guide tube; A main body that is arranged so as to be close to or separate from the valve port of the valve seat and guided to the inner periphery of the guide tube, a taper that controls the opening area of the valve port, and an end and a taper of the main body A needle member having at least one overhanging portion formed between the base portion and the base portion so as to be orthogonal to the flow direction of the refrigerant and guiding the refrigerant from the valve port to the communication hole; Disposed between the end portion of the over blanking, a biasing member for biasing in a direction coming close to the needle member to the valve port of the valve seat, with the diameter of the projecting portion of the needle member, the needle member It is characterized by being set smaller than the diameter of the main body. Moreover, the overhang | projection part of a needle member may be distribute | arranged adjacent to a communicating hole in the expansion part connected to the valve port in a guide tube. A plurality of protruding portions of the needle member may be formed in parallel to each other. Furthermore, the communication path which makes the pressure in the enlarged portion in the guide tube substantially the same as the pressure in the portion where the urging member in the guide tube is arranged is the outer peripheral portion of the main body portion of the needle member and the inner peripheral portion of the guide tube. Between the two.

  A refrigeration cycle system including a throttle device according to the present invention includes an evaporator, a compressor, and a condenser, and the above-described throttle device is disposed between the outlet of the condenser and the inlet of the evaporator. It shall be provided in the piping.

  According to the throttle device and the refrigeration cycle system including the same according to the present invention, the needle member is formed between the end of the main body and the base of the tapered portion so as to be orthogonal to the flow direction of the refrigerant. Since it has at least one overhanging part that guides the refrigerant from the port to the communication hole, foreign substances such as the eluate or wear powder of components contained in the refrigerant and refrigeration oil, and the compound of this eluate and wear powder from the valve port Can also be prevented from adhering to the sliding portion of the expansion device arranged on the downstream side.

It is sectional drawing which shows the structure of 1st Example of the aperture_diaphragm | restriction apparatus which concerns on this invention. It is a figure which shows roughly the structure of an example of the refrigerating-cycle system to which each Example of the expansion device which concerns on this invention is applied. It is sectional drawing with which it uses for operation | movement description in the example shown by FIG. It is sectional drawing with which it uses for operation | movement description of a comparative example. It is sectional drawing which shows the structure of 2nd Example of the aperture_diaphragm | restriction apparatus which concerns on this invention. It is sectional drawing which shows the structure of 3rd Example of the aperture_diaphragm | restriction apparatus which concerns on this invention. It is sectional drawing which shows the structure of 4th Example of the aperture_diaphragm | restriction apparatus which concerns on this invention.

  FIG. 1 shows a configuration of a first embodiment of a throttle device according to the present invention applied to an example of a refrigeration cycle system.

  For example, as shown in FIG. 2, the expansion device is disposed between the outlet of the condenser 6 and the inlet of the evaporator 2 in the piping of the refrigeration cycle system. The throttle device is joined to the primary side pipe Du1 at one end 10E1 of the tube body 10 to be described later, and joined to the secondary side pipe Du2 at the other end 10E2 of the tube body 10 from which the refrigerant is discharged. The primary side pipe Du1 connects the outlet of the condenser 6 and the throttle device, and the secondary side pipe Du2 connects the inlet of the evaporator 2 and the throttle device. Between the outlet of the evaporator 2 and the inlet of the condenser 6, as shown in FIG. 2, a pipe Du3 joined to the outlet of the evaporator 2 and a pipe Du4 joined to the inlet of the condenser 6 Thus, the compressor 4 is connected. The compressor 4 is driven and controlled by a control unit (not shown). Thereby, the refrigerant | coolant in a refrigerating-cycle system will be circulated along the arrow shown by FIG. 2, for example.

  As shown in the enlarged view of FIG. 1, the expansion device includes a tube body 10 joined to the piping of the above-described refrigeration cycle system, a guide tube 18 fixed to the inner periphery of the tube body 10, and a guide tube 18. The valve seat 18V that forms a refrigerant flow rate adjusting unit that is integrally formed at the end portion close to the primary side pipe Du1 and adjusts the flow rate of the refrigerant, the needle member 20, and the direction in which the needle member 20 approaches the valve seat 18V The main elements are a coil spring 16 that is biased toward the end, a spring receiving member 12 that supports one end of the coil spring 16, and a stopper member 22 that receives an end surface of a cylindrical large-diameter portion 20P2 (described later) of the needle member 20. It is configured to include as.

  The tube body 10 having a predetermined length and diameter is made of, for example, a copper pipe, a stainless steel pipe, or an aluminum pipe, and is connected to the condenser 6 at one end 10E1 into which the refrigerant is introduced. It is joined to Du1 and joined to the secondary pipe Du2 connected to the evaporator 2 at the other end 10E2 from which the refrigerant is discharged.

  An outer peripheral portion of a fixing portion 18A of a guide tube 18 to be described later is fixed to an intermediate portion that is separated from the one end 10E1 in the inner peripheral portion of the tube main body 10 by a predetermined distance. The fixing portion 18A of the guide tube 18 is fixed by the protrusion formed by the depression 10CA1 of the tube main body 10 by caulking processing biting into the outer peripheral portion of the fixing portion 18A.

  The guide tube 18 is made of a material such as copper, brass, aluminum, or stainless steel by machining. A cylindrical needle member accommodating portion 18D on the downstream side of the fixed portion 18A in the guide tube 18 and a cylindrical stopper member accommodating portion 18U on the upstream side of the fixed portion 18A are respectively arranged on the inner diameter of the tube body 10. The outer diameter is smaller than that. The guide tube 18 has a spring receiving member 12 on the inner peripheral portion of the end of the needle member accommodating portion 18D closest to the other end 10E2 of the tube main body 10 and is the stopper member accommodating portion closest to the one end 10E1 of the tube main body 10. A stopper member 22 is provided on the inner periphery of the end of 18U. The above-described needle member accommodating portion 18D, stopper member accommodating portion 18U, and fixing portion 18A in the guide tube 18 are integrally formed.

  The valve seat 18V formed in the fixed portion 18A has a valve port 18P into which a tapered portion 20P1 (described later) of the needle member 20 is inserted at the center of the inside. The valve port 18P has a circular opening that penetrates along the central axis of the valve seat 18V with a predetermined uniform diameter. The valve port 18P is not limited to such an example. For example, the valve port 18P may pierce toward the one end 10E1 along the central axis of the valve seat 18V. A divergent portion whose inner diameter gradually increases toward the upstream side than the diameter of the valve port 18P is formed on the inner side of the fixed portion 18A at the upstream portion of the guide tube 18 from the valve port 18P.

  A stopper member 22 is fixed to the inner peripheral portion of the stopper member accommodating portion 18U. The stopper member 22 is fixed by the protrusion formed by the depression 18CA2 of the stopper member housing portion 18U by caulking process biting into the outer peripheral portion thereof. The stopper member 22 is made of, for example, a metal material and has a substantially circular cross section. A substantially flat surface is formed on both end surfaces of the stopper member 22 formed so as to be orthogonal to the refrigerant flow. One end face of the both end faces of the stopper member 22 is in contact with the end face of the cylindrical large diameter portion 20P2 of the needle member 20 when the tapered portion 20P1 of the needle member 20 is close to the valve port 18P. The stopper member 22 has a flat surface 22FS spaced apart and facing each other on a part of the outer peripheral surface. Thereby, the flow path of the refrigerant is formed between the inner peripheral surface of the guide tube 18 and each flat surface 22FS of the stopper member 22.

  As shown in FIG. 1, an enlarged portion 18M having an inner diameter larger than the diameter of the valve port 18P is formed on the inner side of the needle member housing portion 18D in the downstream portion of the guide tube 18 from the valve seat 18V. ing. In the enlarged portion 18M, a protruding portion 20F of the needle member 20 described later is disposed.

  A communication hole 18c is formed between the spring receiving member 12 and the above-described valve seat 18V in the inner peripheral portion of the needle member housing portion 18D so as to face the above-described enlarged portion 18M immediately above the valve seat 18V. The communication hole 18c penetrates the needle member accommodating portion 18D of the guide tube 18 in the radial direction, thereby allowing the inner peripheral portion of the guide tube 18, the valve port 18P, and the above-described enlarged portion 18M to be connected to the inside of the tube main body 10. The peripheral portion communicates with the outer peripheral portion of the needle member housing portion 18D of the guide tube 18.

  The spring receiving member 12 is fixed to the inner peripheral portion of the needle member accommodating portion 18D by the protrusion formed by the depression 18CA1 of the needle member accommodating portion 18D in the guide tube 18 by caulking process biting into the outer peripheral portion. The spring receiving member 12 as the urging member supporting portion has a spring guide 12b with which one end of the coil spring 16 is engaged. The other end of the coil spring 16 is engaged with the spring guide portion 20D1 of the needle member 20. A communicating hole 18b having a diameter smaller than the diameter of the communicating hole 18c is formed in a portion of the needle member accommodating portion 18D facing the coil spring 16 so as to penetrate in the radial direction of the guide tube 18. As a result, the inside of the needle member accommodating portion 18D, the inner peripheral portion of the tube main body 10, and the outer peripheral portion of the guide tube 18 in the needle member accommodating portion 18D are communicated.

  The needle member 20 is made of a material such as brass or stainless steel, for example, by machining, and is provided with a columnar main body portion 20A slidably disposed on the inner peripheral portion of the needle member housing portion 18D, and a main body portion. A tapered portion 20P1 that is connected to 20A through an overhang portion 20F, which will be described later, and that faces the valve seat 18V, a cylindrical large-diameter portion 20P2 that is formed at one end of the tapered portion 20P1, and the other end of the coil spring 16 The projecting spring guide portion 20D1 formed at the end portion of the main body portion 20A facing the main body 20A and the projecting portion 20F formed between the main body portion 20A and the base portion of the tapered portion 20P1 are mainly configured. ing.

  The minimum diameter portion of the tapered portion 20P1 is set to be the same as the diameter of the connecting portion of the cylindrical large diameter portion 20P2. As shown in FIG. 1, the frustoconical taper 20P1 having a predetermined taper angle is larger than the diameter of the valve port 18P when the end surface of the cylindrical large-diameter portion 20P2 is brought into contact with the end surface of the stopper member 22. A base having a large diameter is provided at a predetermined distance from the valve port 18P. A cylindrical large-diameter portion 20P2 having a cylindrical portion of a predetermined length having a uniform diameter is formed continuously with the minimum diameter portion in the tapered portion 20P1. The diameter of the end face of the cylindrical large diameter portion 20P2 is set to be larger than the minimum diameter portion of the tapered portion 20P1. The length from the position corresponding to the opening end of the valve port 18P in the tapered portion 20P1 to the end face of the above-described cylindrical large diameter portion 20P2 is set to a predetermined length.

  When the end surface of the cylindrical large-diameter portion 20P2 is brought into contact with the flat end surface of the stopper member 22, the tip 20P1 is positioned at a position corresponding to the opening end of the valve port 18P in the outer peripheral portion of the tip 20P1 of the needle member 20. The outer peripheral portion is disposed so as to form a predetermined gap with respect to the peripheral edge of the opening end portion of the valve port 18P. At this time, a throttle portion described later is formed between the tapered portion 20P1 of the needle member 20 and the opening end portion of the valve port 18P. When the pressure of the refrigerant in the tube body 10 is equal to or less than a predetermined value, the end surface of the cylindrical large-diameter portion 20P2 is at a predetermined pressure corresponding to the difference between the biasing force of the coil spring 16 and the pressure of the refrigerant from the primary side pipe Du1. The stopper member 22 is in contact with the flat surface.

  The predetermined amount of bleed passing through the throttle portion is set by the amount of the predetermined gap formed with respect to the peripheral edge of the opening end of the valve port 18P. Further, since the cylindrical large diameter portion 20P2 of the needle member 20 is in contact with the flat surface of the stopper member 22, an undesired pressure from the secondary side acts on the needle member 20, and the tapered portion 20P1 of the needle member 20 Biting into the open end of the valve port 18P of the valve seat 18V is avoided.

  The other end portion of the coil spring 16 is engaged with the spring guide portion 20 </ b> D <b> 1 of the needle member 20. A spring guide portion 12 b of the spring receiving member 12 is engaged with one end portion of the coil spring 16. The contact portion 20D2 connected to the spring guide portion 20D1 and the tip of the spring guide portion 12b are separated by a predetermined distance. Accordingly, if the needle member 20 is moved toward the spring guide portion 12b by a predetermined value or more, the end surface of the contact portion 20D2 and the tip end of the spring guide portion 12b come into contact with each other, so that the needle member 20 moves. Will be regulated. Therefore, it is avoided that the coil spring 16 is excessively compressed to a predetermined value or more.

  The spring guide portion 20D1 of the needle member 20 is provided with a spring member 24 that decelerates the moving speed of the needle member 20. The spring member 24 is made of, for example, a thin plate metal material, and has three contact pieces formed integrally with an annular fixed piece. The spring guide portion 20D1 is inserted into the hole of the fixed piece. The three contact pieces are spaced apart at an equal angle along the circumferential direction of the fixed piece. Thus, the moving speed of the needle member 20 is decelerated by the tips of the three elastically displaceable contact pieces slidingly contacting the inner peripheral surface of the guide tube 18 with a predetermined load.

  As shown in FIG. 3, the protruding portion 20 </ b> F of the needle member 20 is formed in a substantially annular shape so as to form a disc-shaped contour. The diameter of the overhang 20F is set slightly smaller than the diameter of the main body 20A. For example, the diameter of the overhang 20F is set to be smaller by about 0.2 to 0.6 mm than the diameter of the main body 20A. Note that this set value is set based on the eluate and the like that will accumulate in the guide tube 18 when the refrigeration cycle system is operated for a predetermined long period of time. Even if eluate or the like accumulates at a location corresponding to the portion 20F, the deposited elution portion or the like has a value that does not contact the overhanging portion 20F. As a result, even if the eluted material adheres to the end of the inner peripheral portion of the needle member housing portion 18D, there is no possibility that the sliding of the needle member 20 is hindered by the overhang portion 20F.

  Further, the overhanging portion 20F is formed through a shaft portion at a position separated from the end of the main body portion 20A by a predetermined distance. When the cylindrical large-diameter portion 20P2 of the needle member 20 is at a position farthest away from the flat surface of the stopper member 22, the position of the overhang portion 20F is set so that its lower end is close to and faces the peripheral edge of the communication hole 18c. Has been. As a result, a part of the refrigerant from the valve port 18P flows into the gap between the inner peripheral portion of the needle member accommodating portion 18D and the outer peripheral portion of the overhang portion 20F, and the other amount is larger than that. As shown by the arrow in FIG. 3, the refrigerant is guided toward the communication hole 18c by the lower end surface and the peripheral edge of the overhang portion 20F. The refrigerant that has flowed into the gap between the inner peripheral portion of the needle member accommodating portion 18D and the outer peripheral portion of the overhang portion 20F is a gap between the outer peripheral portion of the main body portion 20A and the inner peripheral portion of the needle member accommodating portion 18D. It is discharged into the gap between the outer peripheral portion of the needle member accommodating portion 18D and the inner peripheral portion of the tube main body 10 through the inner peripheral portion of the needle member accommodating portion 18D and the communication hole 18b. Thereby, most of the refrigerant from the valve port 18P is discharged to the other end 10E2 through the communication hole 18c of the guide tube 18 through the gap between the outer peripheral portion of the needle member housing portion 18D and the inner peripheral portion of the tube body 10. The Therefore, the eluate or wear powder formed by the elution of the components contained in the refrigerant or the refrigerating machine oil, or the compound of the eluate and the wear powder, etc., are located on the upstream and downstream ends of the main body 20A of the needle member 20. Adhering to and depositing on the substrate is further avoided. Moreover, it is also avoided that the above-described eluate and the like bite into the gap between the outer peripheral portion of the main body portion 20A and the inner peripheral portion of the needle member accommodating portion 18D.

  4 shows a throttling device as a comparative example in which a needle member 30 is used instead of the needle member 20 used in the first embodiment of the throttling device according to the present invention. In FIG. 4, the same constituent elements in the example shown in FIG. 3 are denoted by the same reference numerals, and redundant description thereof is omitted.

  The needle member 30 is made of a material similar to the material of the needle member 20 without having an overhanging portion as employed in an example of the present invention, and is slid onto the inner peripheral portion of the needle member accommodating portion 18D. A cylindrical main body portion 30A that is movably disposed, a tapered portion 30P1 that is connected to an end portion of the main body portion 30A via a chamfered portion and faces the valve seat 18V, and one end portion of the tapered portion 30P1 The main component is a cylindrical large-diameter portion 30P2 formed and a protruding spring guide portion 30D1 formed at the end of the main body 30A facing the other end of the coil spring 16.

  The minimum diameter portion of the tapered portion 30P1 is set to be the same as the diameter of the connecting portion of the cylindrical large diameter portion 30P2. The frustoconical tapered portion 30P1 having a predetermined taper angle has a base portion having a diameter larger than the diameter of the valve port 18P when the end surface of the cylindrical large-diameter portion 30P2 is brought into contact with the end surface of the stopper member 22. It is located at a predetermined distance from the port 18P. A cylindrical large-diameter portion 30P2 having a cylindrical portion of a predetermined length having a uniform diameter is formed continuously with the minimum diameter portion in the tapered portion 30P1.

  The other end portion of the coil spring 16 is engaged with the spring guide portion 30 </ b> D <b> 1 of the needle member 30. A spring guide portion 17 b of the spring receiving member 17 is engaged with one end portion of the coil spring 16. The contact portion 30D2 connected to the spring guide portion 30D1 and the tip of the spring guide portion 17b are separated by a predetermined distance. Thereby, if the needle member 30 is moved toward the spring guide portion 17b by a predetermined value or more, the end surface of the contact portion 30D2 and the tip of the spring guide portion 17b come into contact with each other. Will be regulated.

  In such a configuration, as shown in FIG. 4, a part of the refrigerant whose flow is disturbed by passing through the throttle portion is caused by the inner peripheral portion of the valve needle member accommodating portion 18 </ b> D and the outer peripheral portion of the needle member 30. The refrigerant flows directly into the gap between the inner periphery of the valve needle member accommodating portion 18D and discharged through the communication hole 18b, and the other part of the refrigerant is connected to the inner periphery of the tube body 10 through the communication hole 18c. It will be discharged | emitted between the outer peripheral parts of the guide tube 18. FIG. In such a case, due to the operation for a relatively long period of time by the refrigeration cycle system, in the throttling device as this comparative example, the eluate or wear powder formed by elution of the components contained in the refrigerant or refrigerating machine oil, or There is a possibility that the eluents SE1 and SE2, which are compounds of substances and wear powders, adhere and accumulate in the vicinity of the downstream and upstream ends of the main body 30A of the needle member 30 in the inner periphery of the guide tube 18, As a result, in the aperture device as a comparative example, the smooth operation of the needle member 30 may be impaired.

  Furthermore, the outer peripheral portion of the tapered portion 20P1 of the needle member 20 in the first embodiment of the throttling device according to the present invention described above has a differential pressure (the refrigerant inlet pressure on the one end 10E1 side and the refrigerant outlet pressure on the other end 10E2 side). The separation start timing at which the valve port 18P starts to be further separated from the peripheral edge of the opening end of the valve port 18P is set based on the biasing force of the coil spring 16. The spring constant of the coil spring 16 is set to a predetermined value.

  Further, when the end surface of the cylindrical large diameter portion 20P2 comes into contact with the stopper member 22, a biasing force in the valve closing direction by the coil spring 16 acts on the contact surface between the stopper member 22 and the cylindrical large diameter portion 20P2.

  The adjustment of the biasing force of the coil spring 16, that is, the adjustment of the reference height (set length) of the coil spring 16 corresponding to each refrigerant is performed, for example, in the following procedure. The reference height refers to the height of the coil spring 16 set so as to be the above-described predetermined separation timing of the tapered portion 20P1 of the needle member 20 corresponding to each refrigerant.

  First, when the stopper member 22 is fixed to the inner peripheral portion 18a of the stopper member accommodating portion 18U of the guide tube 18, the cylindrical large diameter portion 20P2 of the needle member 20 is first inserted into the valve port 18P. Then, the needle member 20 is pressed against the valve seat 18V using a coil spring or the like, and then the guide tube 18 into which the stopper member 22 is inserted is, for example, a bleed flow rate measuring device / caulking device using air as a fluid ( After adjusting the position of the stopper member 22 with respect to the guide tube 18 so that the air flow rate is equal to the target bleed flow rate, the stopper member is in contact with the end face of the cylindrical large diameter portion 20P2. Adjustment of the bleed flow rate is completed by caulking and fixing 22 to the guide tube 18.

  When the spring receiving member 12 is fixed, the guide tube 18 to which the stopper member 22 is fixed is disposed in advance in a state where it is arranged in a predetermined performance measurement / caulking device (not shown) using air as a fluid, for example. After adjusting the position of the spring receiving member 12 with respect to the guide tube 18 based on detection of the air flow rate in a state where a prescribed pressure is applied, the spring receiving member 12 is caulked and fixed, whereby the spring of the coil spring 16 is fixed. The length adjustment is completed.

  Accordingly, since an adjustment screw or the like for adjusting the spring length of the coil spring 16 is not required, the valve opening start pressure corresponding to each refrigerant can be adjusted, and the structure of the expansion device can be simplified and the manufacturing cost can be simplified. Can be reduced.

  In such a configuration, when the force acting on the needle member 20 due to the pressure of the refrigerant does not exceed the urging force of the coil spring 16, the refrigerant is supplied along the direction indicated by the arrow through the primary side pipe Du1 in FIG. As shown in FIG. 1, the pressure of the refrigerant passes through one end 10E1 of the tube main body 10 and between the inner peripheral portion 10a of the tube main body 10 and the outer peripheral portion of the guide tube 18 through the above-mentioned throttle portion and the communication passage 18c. Then, the pressure is reduced, and then the refrigerant is discharged from the other end 10E2 by a predetermined bleed amount through between the outer peripheral surface of the guide tube 18 and the inner peripheral surface 10a of the tube body 10.

  Further, when the force acting on the needle member 20 due to the pressure of the refrigerant exceeds the urging force of the coil spring 16, the refrigerant flowing through the above-mentioned throttle portion is allowed to flow from the peripheral edge of the valve port 18P as shown in FIGS. Further, the needle member 20 is pressed in the direction of separation. As a result, the flow rate increases rapidly as the differential pressure increases.

  When the outer peripheral portion of the tapered portion 20P1 of the needle member 20 is separated from the peripheral edge of the open end portion of the valve port 18P as described above, the tapered portion 20P1 of the needle member 20 and the open end portion of the valve port 18P are separated from each other. In the meantime, a throttle part whose opening degree is variable according to the refrigerant pressure is formed. The throttle portion refers to a portion (narrowest portion) where the intersection of the perpendicular line from the peripheral edge of the valve port 18P to the bus bar of the tapered detail 20P1 and the bus bar of the tapered detail 20P1 is closest to the edge of the valve port 18P. The area of the conical surface drawn by the perpendicular is the opening area of the diaphragm. The calculation of the opening area is based on the outer peripheral portion of the tapered portion 20P1 formed when the force acting on the needle member 20 due to the refrigerant pressure does not exceed the biasing force of the coil spring 16 and the opening end portion of the valve port 18P. The same applies to the gap formed between the periphery.

  FIG. 5 shows the configuration of a second embodiment of the expansion device according to the present invention applied to an example of a refrigeration cycle system.

  In the example shown in FIG. 1, the needle member 20 has a one-stage overhang 20F between the end of the main body 20A and the base of the tapered portion 20P1, but instead, FIG. In the example shown in FIG. 4, the needle member 40 has two protruding portions 40F1 and 40F2 spaced apart from each other between the end of the main body 40A and the base of the tapered portion 40P1. In FIG. 5, the same components in the example shown in FIG. 1 are denoted by the same reference numerals, and redundant description thereof is omitted.

  For example, as shown in FIG. 2, the expansion device is disposed between the outlet of the condenser 6 and the inlet of the evaporator 2 in the piping of the refrigeration cycle system, as in the above example.

  The expansion device includes a tube main body 10 joined to the above-described refrigeration cycle system pipe, a guide tube 18 ′ fixed to the inner peripheral portion of the tube main body 10, and an end portion of the guide tube 18 ′ near the primary side pipe Du <b> 1. The valve seat 18′V that forms a refrigerant flow rate adjusting unit that adjusts the flow rate of the refrigerant, and the needle member 40 and the coil that urges the needle member 40 in the direction of approaching the valve seat 18′V. When the force acting on the needle member 40 due to the pressure of the refrigerant does not exceed the urging force of the coil spring 16, the cylinder of the needle member 40. The stopper member 22 that receives the end surface of the large-diameter portion 40P2 is included as a main element.

  The outer peripheral portion of the fixing portion 18′A of the guide tube 18 ′ having an outer diameter smaller than the inner diameter of the tube main body 10 is fixed to an intermediate portion separated from the one end 10E1 in the inner peripheral portion of the tube main body 10 by a predetermined distance. ing. The guide tube 18 'is fixed by a protrusion formed by the depression 10CA1 of the tube main body 10 by caulking, biting into the outer peripheral portion of the fixing portion 18'A. A spring receiving member 12 'is fixed to the inner peripheral portion of the end portion of the needle member housing portion 18'D that is closest to the other end 10E2 of the tube body 10. The spring receiving member 12 ′ is fixed by a protrusion formed by a cylindrical depression 18 ′ CA 1 in the guide tube 18 ′ by caulking, which bites into the outer periphery thereof.

  The guide tube 18 'is made by machining with a material such as copper, brass, aluminum, or stainless steel. A cylindrical needle member accommodating portion 18′D on the downstream side of the fixed portion 18′A in the guide tube 18 ′ and a cylindrical stopper member accommodating portion 18′U on the upstream side of the fixed portion 18′A. Each has an outer diameter smaller than the inner diameter of the tube body 10. The guide tube 18 ′ has a spring receiving member 12 ′ on the inner peripheral portion of the end of the needle member housing portion 18 ′ D closest to the other end 10 E 2 of the tube main body 10, and is closest to the one end 10 E 1 of the tube main body 10. A stopper member 22 is provided on the inner periphery of the end of the stopper member housing portion 18'U. The above-described needle member housing portion 18′D, stopper member housing portion 18′U, and fixing portion 18′A in the guide tube 18 ′ are integrally formed.

  The valve seat 18′V formed in the fixed portion 18′A has a valve port 18′P into which a later-described detail 40P1 of the needle member 40 is inserted at the inner central portion. The valve port 18'P has a circular opening that penetrates along the central axis of the valve seat 18'V with a predetermined uniform diameter. In addition, valve port 18'P is not restricted to such an example, For example, you may penetrate in a divergent shape toward the one end 10E1 along the central axis of valve seat 18'V. In the upstream portion of the guide tube 18 ′ from the valve port 18 ′ P, a divergent portion whose inner diameter gradually increases toward the upstream side from the diameter of the valve port 18 ′ P is formed inside the fixed portion 18 ′ A. Is formed.

  A stopper member 22 is fixed to the inner peripheral portion 18'a of the stopper member housing portion 18'U. One end face of the stopper member 22 has a tapered portion 40P1 of the needle member 40 close to the valve port 18'P (the force acting on the needle member 40 due to the pressure of the refrigerant is applied to the coil spring 16). When the force does not exceed), the end surface of the cylindrical large-diameter portion 40P2 of the needle member 40 is abutted.

  As shown in FIG. 5, an enlarged portion 18 ′ M having an inner diameter larger than the diameter of the valve port 18 ′ P is provided in the guide tube 18 ′ on the downstream side of the valve seat 18 ′ V. It is formed inside the portion 18'D. As shown by a two-dot chain line and a solid line in FIG. 5, overhanging portions 40F1 and 40F2 of the needle member 40 described later are arranged in the enlarged portion 18′M.

  Between the spring receiving member 12 'and the above-described valve seat 18'V in the inner peripheral portion of the needle member accommodating portion 18'D, a communication hole 18'c is provided directly above the valve seat 18'V. It is formed facing 'M. The communication hole 18′c penetrates the needle member housing portion 18′D of the guide tube 18 ′ in the radial direction, thereby allowing the inner peripheral portion of the guide tube 18 ′, the valve port 18′P, and the above-described enlarged portion. 18'M is connected between the inner peripheral part of the tube main body 10, and the outer peripheral part in needle member accommodating part 18'D of guide tube 18 '.

  The spring receiving member 12 ′ has an inner periphery of the needle member housing portion 18 ′ D formed by a protrusion formed by the depression 18 ′ CA 1 of the needle member housing portion 18 ′ D in the guide tube 18 ′ by caulking. It is fixed to the part. The spring receiving member 12 ′ as the urging member supporting portion has a spring guide 12 ′ b with which one end of the coil spring 16 is engaged. The other end of the coil spring 16 is engaged with a spring guide portion 40D1 of the needle member 40. A communicating hole 18 ′ b having a diameter smaller than the diameter of the communicating hole 18 ′ c is formed in a portion of the needle member housing portion 18 ′ D facing the coil spring 16 so as to penetrate in the radial direction of the guide tube 18. ing. Thereby, the clearance gap between the inner side of needle member accommodating part 18'D, the inner peripheral part of the tube main body 10, and the outer peripheral part in needle member accommodating part 18'D of guide tube 18 'will communicate.

  Further, an annular recess 18′R is formed in a portion closer to an end portion of a main body portion 40A of the needle member 40 to be described later than the communication hole 18′b in the inner peripheral portion of the needle member housing portion 18′D. .

  The needle member 40 is made of a material such as brass or stainless steel by machining, for example, and a columnar main body portion 40A that is slidably disposed on the inner peripheral portion of the needle member housing portion 18′D. A tapered portion 40P1 which is connected to the main body portion 40A via projecting portions 40F1 and 40F2 which will be described later and is formed to face the valve seat 18'V, and a cylindrical large diameter portion 40P2 which is formed at one end of the tapered portion 40P1; A protruding spring guide portion 40D1 formed at the end of the main body portion 40A facing the other end of the coil spring 16, and a two-stage overhang portion 40F1 formed between the main body portion 40A and the base of the tapered portion 40P1. And 40F2 as main elements.

  The minimum diameter portion of the tapered portion 40P1 is set to be the same as the diameter of the connecting portion of the cylindrical large diameter portion 40P2. When the end surface of the cylindrical large-diameter portion 40P2 is brought into contact with the end surface of the stopper member 22, as shown by a two-dot chain line in FIG. A base having a diameter larger than the diameter of 'P is provided at a position separated from the valve port 18'P by a predetermined distance. A cylindrical large-diameter portion 40P2 having a cylindrical portion having a uniform diameter and a predetermined length is continuously formed at the minimum diameter portion of the tapered portion 40P1. The diameter of the end face of the cylindrical large diameter portion 40P2 is set to be larger than the minimum diameter portion of the tapered portion 40P1. The length from the position corresponding to the open end of the valve port 18′P in the tapered portion 40P1 to the end face of the above-described cylindrical large diameter portion 40P2 is set to a predetermined length.

  When the end surface of the cylindrical large-diameter portion 40P2 is brought into contact with the flat end surface of the stopper member 22, the tapered portion is located at the position corresponding to the opening end portion of the valve port 18'P on the outer peripheral portion of the tapered portion 40P1 of the needle member 40. The outer peripheral part of 40P1 is arrange | positioned so that a predetermined clearance may be formed with respect to the periphery of the opening edge part of valve port 18'P. At this time, a throttle portion described later is formed between the tapered portion 40P1 of the needle member 40 and the opening end portion of the valve port 18'P. When the pressure of the refrigerant in the tube body 10 is equal to or less than a predetermined value, the end surface of the cylindrical large-diameter portion 40P2 is at a predetermined pressure corresponding to the difference between the urging force of the coil spring 16 and the pressure of the refrigerant from the primary side pipe Du1. The stopper member 22 is in contact with the flat surface.

  The predetermined amount of bleed passing through the throttle portion is set by the amount of the predetermined gap formed with respect to the peripheral edge of the opening end of the valve port 18′P. Further, since the cylindrical large diameter portion 40P2 of the needle member 40 is in contact with the flat surface of the stopper member 22, an undesired pressure from the secondary side acts on the needle member 40, and the tapered portion 40P1 of the needle member 40 is Biting into the open end of the valve port 18'P of the valve seat 18'V is avoided.

  As shown in FIG. 5, the overhang portions 40F1 and 40F2 in the needle member 40 are formed in parallel to each other at a predetermined interval perpendicular to the central axis. The diameters of the overhang portions 40F1 and 40F2 are set slightly smaller than the diameter of the main body portion 40A. Thereby, even if an eluate etc. adhere to the edge part of the inner peripheral part of needle member accommodating part 18'D, there is no possibility that the function of overhang | projection part 40F1 and 40F2 may be inhibited. The overhanging portion 40F1 is formed in a substantially annular shape so as to form a disc-shaped contour, and is formed at a position separated from the end of the main body portion 40A by a predetermined distance. The overhang portion 40F2 is separated from the overhang portion 40F1 by a predetermined distance and is connected to the base portion of the tip detail 40P1. The portions between the overhanging portion 40F1 and the main body portion 40A and between the overhanging portion 40F1 and the overhanging portion 40F2 are smaller than the diameters of the overhanging portions 40F1 and 40F2, respectively. They are connected by a shaft portion having a diameter substantially the same as the diameter of the base portion. As described above, the needle member 40 includes the two-stage overhang portions 40F1 and 40F2, so that the inner peripheral portion of the needle member housing portion 18'D and the overhang portions 40F1 and 40F2 are compared with the example shown in FIG. The quantity of the refrigerant | coolant which passes between between outer peripheral parts is reduced.

  When the cylindrical large-diameter portion 40P2 of the needle member 40 is at a position farthest from the flat surface of the stopper member 22, the position of the overhang portion 40F2 is such that its lower end is close to and faces the peripheral edge of the communication hole 18'c. Is set to Thereby, a part of the refrigerant from the valve port 18′P flows into the gap between the inner peripheral portion of the needle member accommodating portion 18′D and the outer peripheral portions of the overhang portions 40F1 and 40F2, and more than that. The other amount of the refrigerant is guided toward the communication hole 18′c by the lower end surface and the peripheral edge of the overhang portion 40F2. The refrigerant that has flowed into the gap between the inner peripheral portion of the needle member accommodating portion 18′D and the outer peripheral portions of the overhang portions 40F1 and 40F2 is the outer peripheral portion of the main body portion 40A and the inner peripheral portion of the needle member accommodating portion 18′D. Between the outer peripheral portion of the needle member accommodating portion 18'D and the inner peripheral portion 10a of the tube body 10 through the communication hole 18'b. To be released. As a result, most of the refrigerant from the valve port 18 ′ P passes through the communication hole 18 ′ c of the guide tube 18 ′ and the gap between the outer peripheral portion of the needle member housing portion 18 ′ D and the inner peripheral portion of the tube main body 10. Through the other end 10E2. Therefore, the eluate or wear powder formed by elution of the components contained in the refrigerant or the refrigerating machine oil, or the compound of the eluate and wear powder, etc., are located at the upstream and downstream ends of the main body 40A of the needle member 40. Adhering to and depositing on the substrate is further avoided. Moreover, it is also avoided that the above-described eluate and the like bite into the gap between the outer peripheral portion of the main body portion 40A and the inner peripheral portion of the needle member accommodating portion 18′D.

  FIG. 6 shows the configuration of a third embodiment of the expansion device according to the present invention applied to an example of a refrigeration cycle system.

  In the example shown in FIG. 1, the guide tube 18 has the communication hole 18b. Instead, in the example shown in FIG. 6, the guide tube 28 has such a communication hole. In addition, the main body portion 50A of the needle member 50 has a flat surface 50FS that faces the inner peripheral surface of the needle member housing portion 28D of the guide tube 28. In FIG. 6, the same components in the example shown in FIG. 1 are denoted by the same reference numerals, and redundant description thereof is omitted.

  For example, as shown in FIG. 2, the expansion device is disposed between the outlet of the condenser 6 and the inlet of the evaporator 2 in the piping of the refrigeration cycle system.

  As shown in an enlarged view in FIG. 6, the expansion device includes a tube main body 10 joined to the piping of the above-described refrigeration cycle system, a guide tube 28 fixed to the inner peripheral portion of the tube main body 10, and a guide tube 28. The valve seat 28V that forms a refrigerant flow rate adjusting unit that is integrally formed at the end portion near the primary side pipe Du1 and adjusts the flow rate of the refrigerant, the needle member 50, and the direction in which the needle member 50 approaches the valve seat 28V The coil spring 16 that urges the coil spring, the spring receiving member 12 that supports one end of the coil spring 16, and the stopper member 22 that receives the end face of a cylindrical large-diameter portion 50P2 (described later) of the needle member 50 are the main elements. It is configured to include as.

  An outer peripheral portion of a fixing portion 28A of a guide tube 28 to be described later is fixed to an intermediate portion spaced from the one end 10E1 in the inner peripheral portion of the tube main body 10 by a predetermined distance. The fixing portion 28A of the guide tube 28 is fixed by a protrusion formed by the depression 10CA1 of the tube main body 10 by caulking processing biting into the outer peripheral portion of the fixing portion 28A.

  The guide tube 28 is made by machining with a material such as copper, brass, aluminum, or stainless steel. The cylindrical needle member accommodating portion 28D on the downstream side of the fixed portion 28A in the guide tube 28 and the cylindrical stopper member accommodating portion 28U on the upstream side of the fixed portion 28A are respectively arranged on the inner diameter of the tube body 10. The outer diameter is smaller than that. The guide tube 28 has a spring receiving member 12 on the inner peripheral portion of the end of the needle member accommodating portion 28D closest to the other end 10E2 of the tube main body 10, and the stopper member accommodating portion closest to the one end 10E1 of the tube main body 10. A stopper member 22 is provided on the inner periphery of the end of 28U. The needle member housing portion 28D, the stopper member housing portion 28U, and the fixing portion 28A in the guide tube 28 are integrally formed.

  The valve seat 28V formed in the fixed portion 28A has a valve port 28P into which a tapered portion 50P1 (described later) of the needle member 50 is inserted at an inner central portion. The valve port 28P has a circular opening penetrating along the central axis of the valve seat 28V with a predetermined uniform diameter. The valve port 28P is not limited to such an example. For example, the valve port 28P may penetrate in a divergent shape toward the one end 10E1 along the central axis of the valve seat 28V. In the upstream portion of the guide tube 28 from the valve port 28P, a divergent portion whose inner diameter gradually increases toward the upstream side than the diameter of the valve port 28P is formed inside the fixed portion 28A.

  A stopper member 22 is fixed to the inner peripheral portion of the stopper member accommodating portion 28U. One end face of the both end faces of the stopper member 22 is in contact with the end face of the cylindrical large diameter portion 50P2 of the needle member 50 when the tapered portion 50P1 of the needle member 50 is close to the valve port 28P. The stopper member 22 has a flat surface 22FS spaced apart and facing each other on a part of the outer peripheral surface. Thereby, the flow path of the refrigerant is formed between the inner peripheral surface of the guide tube 28 and each flat surface 22FS of the stopper member 22.

  As shown in FIG. 6, an enlarged portion 28M having an inner diameter larger than the diameter of the valve port 28P is formed on the inner side of the needle member housing portion 28D in the downstream portion of the guide tube 28 from the valve seat 28V. ing. In the enlarged portion 28M, a protruding portion 50F of a needle member 50 described later is disposed.

  A communication hole 28c is formed between the spring receiving member 12 and the above-described valve seat 28V in the inner peripheral portion of the needle member housing portion 28D, directly above the valve seat 28V and facing the above-described enlarged portion 28M. The communication hole 28c penetrates the needle member accommodating portion 28D of the guide tube 28 in the radial direction, thereby allowing the inner peripheral portion of the guide tube 28, the valve port 28P, and the above-described enlarged portion 28M to be connected to the inside of the tube main body 10. The peripheral portion communicates with the outer peripheral portion of the needle member housing portion 28 </ b> D of the guide tube 28.

  The spring receiving member 12 is fixed to the inner peripheral portion of the needle member accommodating portion 28D by the protrusion formed by the depression 28CA1 of the needle member accommodating portion 28D in the guide tube 28 by caulking process biting into the outer peripheral portion. The other end of the coil spring 16 is engaged with a spring guide portion 50D1 of the needle member 50.

  The needle member 50 is made of a material such as brass or stainless steel, for example, by machining, and is provided with a columnar main body portion 50A that is slidably disposed on the inner peripheral portion of the needle member housing portion 28D, and a main body portion. A tapered portion 50P1 that is connected to the valve seat 28V through a projecting portion 50F, which will be described later, and a cylindrical large diameter portion 50P2 that is formed at one end of the tapered portion 50P1, and the other end of the coil spring 16 The projecting spring guide portion 50D1 formed at the end of the main body portion 50A facing the main body 50A and the projecting portion 50F formed between the main body portion 50A and the base portion of the tapered portion 50P1 are mainly configured. ing.

  The main body portion 50A having a substantially D-shaped cross section has a flat surface 50FS at a position separated from the central axis by a predetermined distance. The flat surface 50FS extends from end to end along its central axis. As a result, the main body portion in which the communication path that connects the above-described enlarged portion 28M and the inner peripheral portion of the needle member accommodating portion 28D in which the coil spring 16 is disposed faces the inner peripheral portion of the needle member accommodating portion 28D in the guide tube 28. It is formed between the flat surface 50FS of 50A.

  The minimum diameter portion of the tapered portion 50P1 is set to be the same as the diameter of the connecting portion of the cylindrical large diameter portion 50P2. The truncated cone-shaped tapered portion 50P1 having a predetermined taper angle has a base portion having a diameter larger than the diameter of the valve port 28P when the end surface of the cylindrical large-diameter portion 50P2 is brought into contact with the end surface of the stopper member 22. It is located at a predetermined distance from the port 28P. A cylindrical large-diameter portion 50P2 having a cylindrical portion having a uniform diameter and a predetermined length is continuously formed at the minimum diameter portion of the tapered portion 50P1. The diameter of the end face of the cylindrical large diameter portion 50P2 is set to be larger than the minimum diameter portion of the tapered portion 50P1. The length from the position corresponding to the open end of the valve port 28P in the tapered portion 50P1 to the end face of the above-described cylindrical large diameter portion 50P2 is set to a predetermined length.

  When the end surface of the cylindrical large-diameter portion 50P2 is brought into contact with the flat end surface of the stopper member 22, the tapered portion 50P1 is positioned at a position corresponding to the opening end portion of the valve port 28P in the outer peripheral portion of the tapered portion 50P1 of the needle member 50. The outer peripheral portion is disposed so as to form a predetermined gap with respect to the peripheral edge of the opening end portion of the valve port 28P. At this time, a throttle portion described later is formed between the tapered portion 50P1 of the needle member 50 and the opening end portion of the valve port 28P. When the pressure of the refrigerant in the tube body 10 is equal to or lower than a predetermined value, the end surface of the cylindrical large-diameter portion 50P2 has a predetermined pressure corresponding to the difference between the biasing force of the coil spring 16 and the pressure of the refrigerant from the primary side pipe Du1. The stopper member 22 is in contact with the flat surface.

  The predetermined amount of bleed passing through the throttle portion is set by the amount of the predetermined gap formed with respect to the peripheral edge of the opening end of the valve port 28P. Further, since the cylindrical large diameter portion 50P2 of the needle member 50 is in contact with the flat surface of the stopper member 22, an undesired pressure from the secondary side acts on the needle member 50, and the tapered portion 50P1 of the needle member 50 is Biting into the open end of the valve port 28P of the valve seat 28V is avoided.

  The overhang portion 50F of the needle member 50 is formed in a substantially annular shape so as to form a disc-shaped contour. The diameter of the overhang 50F is set to be slightly smaller than the diameter of the main body 50A. Thereby, even if it is a case where an elution thing adheres to the edge part of the inner peripheral part of needle member storage part 28D, there is no possibility that the function of overhang | projection part 50F may be inhibited. The overhang 50F is formed via a shaft at a position spaced a predetermined distance from the end of the main body 50A. When the cylindrical large-diameter portion 50P2 of the needle member 50 is at a position farthest from the flat surface of the stopper member 22, the position of the overhang portion 50F is set so that its lower end is close to and faces the peripheral edge of the communication hole 28c. Has been. Thereby, a part of the refrigerant from the valve port 28P flows into the gap between the inner peripheral portion of the needle member accommodating portion 28D and the outer peripheral portion of the overhang portion 50F, and the other amount is larger than that. The refrigerant is guided toward the communication hole 28c by the lower end surface and the peripheral edge of the overhang portion 50F. Thereby, most of the refrigerant from the valve port 28P is discharged to the other end 10E2 through the communication hole 28c of the guide tube 28 through the gap between the outer peripheral portion of the needle member accommodating portion 28D and the inner peripheral portion of the tube main body 10. The Therefore, the eluate or wear powder formed by elution of the components contained in the refrigerant or the refrigerating machine oil, or the compound of the eluate and wear powder, etc., are located on the upstream and downstream ends of the main body 50A of the needle member 50. Adhering to and depositing on the substrate is further avoided. In addition, the above-described eluate and the like are prevented from biting into the gap between the outer peripheral portion of the main body portion 50A and the inner peripheral portion of the needle member accommodating portion 28D.

  On the other hand, the refrigerant that has flowed into the gap between the inner peripheral portion of the needle member accommodating portion 28D and the outer peripheral portion of the overhang portion 50F is between the outer peripheral portion of the main body portion 50A and the inner peripheral portion of the needle member accommodating portion 28D. The coil spring 16 flows into the inner peripheral portion of the needle member housing portion 28D where the coil spring 16 is disposed through the gap, the communication path formed between the flat surface 50FS of the needle member 50 and the inner peripheral portion of the needle member housing portion 28D. Thereby, since the refrigerant does not pass through the gap between the outer peripheral portion of the main body portion 50A and the inner peripheral portion of the needle member accommodating portion 28D thereafter, an eluate formed by elution of components contained in the refrigerant or the refrigerator oil or It is avoided that the wear powder or the compound of the eluate and the wear powder adheres to and accumulates on the upstream and downstream ends of the main body 50A of the needle member 50.

  At that time, even if the refrigerant leaks from the gap between the outer peripheral portion of the spring receiving member 12 and the inner peripheral portion of the guide tube 28, the pressure of the refrigerant from the valve port 28P is not reduced. Directly acting on the inner peripheral portion of the needle member accommodating portion 28D where the coil spring 16 is disposed, and the pressure inside the enlarged portion 28M and the internal pressure (back) of the needle member accommodating portion 28D where the coil spring 16 is disposed. Pressure) is substantially the same, and instability of the flow characteristics is suppressed.

  In such a configuration, when the force acting on the needle member 50 due to the pressure of the refrigerant does not exceed the biasing force of the coil spring 16, the refrigerant is supplied along the direction indicated by the arrow through the primary side pipe Du1 in FIG. The pressure of the refrigerant is reduced by passing through the throttle part and the communication path 28c between the one end 10E1 of the tube body 10 and the inner periphery 10a of the tube body 10 and the outer periphery of the guide tube 28, and then The refrigerant is discharged from the other end 10E2 by a predetermined bleed amount through the space between the outer peripheral surface of the guide tube 28 and the inner peripheral surface 10a of the tube main body 10.

  Furthermore, when the force acting on the needle member 50 due to the pressure of the refrigerant exceeds the urging force of the coil spring 16, the refrigerant flowing through the above-described throttle portion presses the needle member 50 in a direction further away from the peripheral edge of the valve port 28P. It will be. As a result, when the flow rate is equal to or higher than a predetermined value, the flow rate rapidly increases as the differential pressure increases.

  FIG. 7 shows the configuration of a fourth embodiment of the expansion device according to the present invention applied to an example of a refrigeration cycle system.

  In the example shown in FIG. 6, the peripheral edge at the lower end of the protruding portion 50 </ b> F of the needle member 50 is formed at a right angle, but instead, in the example shown in FIG. 7, the needle member 60. A chamfered portion 60FC is provided on the peripheral edge at the lower end of the overhang portion 60F. In FIG. 7, the same components as those in the example shown in FIG. 6 are denoted by the same reference numerals, and redundant description thereof is omitted.

  The needle member 60 is made of a material such as brass or stainless steel, for example, by machining, and is provided with a cylindrical main body portion 60A slidably disposed on the inner peripheral portion of the needle member housing portion 28D, and a main body portion. A tapered portion 60P1 which is connected to the valve seat 28V through a projecting portion 60F which will be described later on 60A, a cylindrical large diameter portion 60P2 which is formed at one end of the tapered portion 60P1, and the other end of the coil spring 16 The projecting spring guide portion 60D1 formed at the end of the main body portion 60A that faces the main body 60A and the projecting portion 60F formed between the main body portion 60A and the base portion of the tapered portion 60P1 are mainly configured. ing.

  The main body 60A having a substantially D-shaped cross section has a flat surface 60FS at a position separated from the central axis by a predetermined distance. The flat surface 60FS extends from end to end along its central axis. As a result, the main body portion in which the communication path that connects the above-described enlarged portion 28M and the inner peripheral portion of the needle member accommodating portion 28D in which the coil spring 16 is disposed faces the inner peripheral portion of the needle member accommodating portion 28D in the guide tube 28. It is formed between the flat surface 60FS of 60A.

  The minimum diameter portion of the tapered portion 60P1 is set to be the same as the diameter of the connecting portion of the cylindrical large diameter portion 60P2. The truncated cone-shaped tapered portion 60P1 having a predetermined taper angle has a base portion having a diameter larger than the diameter of the valve port 28P when the end surface of the cylindrical large-diameter portion 60P2 is brought into contact with the end surface of the stopper member 22. It is located at a predetermined distance from the port 28P. A cylindrical large-diameter portion 60P2 having a cylindrical portion having a uniform diameter and a predetermined length is continuously formed at the minimum diameter portion of the tapered portion 60P1. The diameter of the end face of the cylindrical large diameter portion 60P2 is set to be larger than the minimum diameter portion of the tapered portion 60P1. The length from the position corresponding to the opening end of the valve port 28P in the tapered portion 60P1 to the end face of the above-described cylindrical large diameter portion 60P2 is set to a predetermined length.

  When the end surface of the cylindrical large-diameter portion 60P2 is brought into contact with the flat end surface of the stopper member 22, the tapered portion 60P1 is positioned at a position corresponding to the opening end portion of the valve port 28P in the outer peripheral portion of the tapered portion 60P1 of the needle member 60. The outer peripheral portion is disposed so as to form a predetermined gap with respect to the peripheral edge of the opening end portion of the valve port 28P. At this time, a throttle portion described later is formed between the tapered portion 60P1 of the needle member 60 and the opening end portion of the valve port 28P. When the pressure of the refrigerant in the tube main body 10 is equal to or lower than a predetermined value, the end surface of the cylindrical large-diameter portion 60P2 is at a predetermined pressure corresponding to the difference between the biasing force of the coil spring 16 and the pressure of the refrigerant from the primary side pipe Du1. The stopper member 22 is in contact with the flat surface.

  The predetermined amount of bleed passing through the throttle portion is set by the amount of the predetermined gap formed with respect to the peripheral edge of the opening end of the valve port 28P. Further, since the cylindrical large diameter portion 60P2 of the needle member 60 is in contact with the flat surface of the stopper member 22, an undesired pressure from the secondary side acts on the needle member 60, and the tapered portion 60P1 of the needle member 60 is Biting into the open end of the valve port 28P of the valve seat 28V is avoided.

  The overhanging portion 60F of the needle member 60 is formed in a substantially annular shape so as to form a disc-shaped contour. The diameter of the overhang 60F is set slightly smaller than the diameter of the main body 60A. Thereby, even if it is a case where an elution thing adheres to the edge part of the inner peripheral part of needle member accommodating part 28D, there is no possibility that the function of overhang | projection part 60F may be inhibited. The overhang 60F is formed via a shaft at a position separated from the end of the main body 60A by a predetermined distance. The overhanging portion 60F has a chamfered portion 60FC at the lower end facing the valve port 28P.

  When the cylindrical large-diameter portion 60P2 of the needle member 60 is at a position farthest from the flat surface of the stopper member 22, the position of the overhang portion 60F is set so that the lower end thereof is close to and faces the peripheral edge of the communication hole 28c. Has been.

  In addition, also in such an Example, there exists an effect similar to having demonstrated in the above-mentioned Example.

  In the above-described example, the overhanging portion 60F has the chamfered portion 60FC at the lower end facing the valve port 28P. However, it is not always necessary to do this, and for example, the refrigerant communicates more smoothly. A concave shape that leads to the hole may be formed at the lower end of the overhang portion 60F.

10 Tube body 12, 12 'Spring receiving member 18, 18', 28 Guide tube 18V, 18'V, 28V Valve seat 18P, 18'P, 28P Valve port 20, 40, 50, 60 Needle member 20F, 40F1, 40F2 , 50F, 60F Overhang portion 50FS, 60FS Flat surface 22 Stopper member

Claims (5)

A tube main body that is arranged in a pipe for supplying a refrigerant and has open ends at both ends communicating with the pipe;
A valve seat having a valve port formed in a guide tube having at least one open end communicating with the tube body;
At least one communication hole formed adjacent to the valve seat in the guide tube and communicating with the inner periphery and the outer periphery of the guide tube;
A main body that is arranged to be close to or away from the valve port of the valve seat and is guided by an inner peripheral portion of the guide tube; a taper that controls an opening area of the valve port; and an end of the main body And a needle member having at least one overhanging portion that is formed so as to be orthogonal to the flow direction of the refrigerant and guides the refrigerant from the valve port to the communication hole.
An urging member that is arranged between the needle member and an end of the guide tube and urges the needle member in a direction approaching the valve port of the valve seat ;
The diameter of the overhang | projection part of the said needle member is set small compared with the diameter of the main-body part of this needle member, The diaphragm | throttle device characterized by the above-mentioned .   2. A throttling device according to claim 1, wherein the protruding portion of the needle member is disposed adjacent to the communication hole in an enlarged portion communicating with the valve port in the guide tube. The diaphragm device according to claim 1, wherein a plurality of protruding portions of the needle member are formed in parallel to each other . A communication path that substantially equalizes the pressure in the enlarged portion of the guide tube and the pressure of the portion of the guide tube where the urging member is disposed is provided between the outer peripheral portion of the body portion of the needle member and the guide tube. The diaphragm device according to claim 2 , wherein the diaphragm device is formed between the inner circumferential portion and the inner circumferential portion . An evaporator, a compressor, and a condenser;
5. A refrigeration cycle system, wherein the expansion device according to claim 1 is provided in a pipe disposed between an outlet of the condenser and an inlet of the evaporator .